[compiler-rt] [compiler-rt][asan] Add wcscpy/wcsncpy; enable wcscat/wcsncat on Windows (PR #160493)

[Yixuan Cao via llvm-commits]

Cao-Wuhui wrote:

Hi! First-time contributor here. Could a maintainer please approve CI workflows (Build and Test Linux/Windows) to run? 
This PR only touches compiler-rt/asan and tests; no changes under .github/workflows. Thanks!

https://github.com/llvm/llvm-project/pull/160493